All five guides to a Perth block
Stake 02 · Garden structures
Patios, sheds and garden structures in WA
In Western Australia a patio, shed, carport or private garage is a Class 10a building, and since 1 July 2026 one valued at less than $50,000 no longer has to be built by a registered building contractor. The building permit rules did not change with it: where a permit is required, the owner must make sure it is obtained from the local government before construction begins.
General information about Western Australia’s rules, not legal or building advice. Building and Energy publishes the rules; your local government assesses a building permit application and can tell you what it needs from you.
What counts as a Class 10a building
The National Construction Code sorts every building into classes, and each part of a building must meet the requirements for its class. Class 10a is the code’s class for a non-habitable building: a private garage, a carport, a shed or the like.
The patio belongs here too. Roofed outdoor areas, which Western Australians usually call patios, are treated as Class 10a buildings. So the roof over the back paving sits in the same class as the shed at the end of the garden.
Who may build one
Since 1 July 2026, the threshold for Class 10a work sits at $50,000. Smaller service providers and “home handyman” businesses can now build sheds, carports, patios, private garages and the like up to that value, and registered building contractors can still do Class 10a work of any value.
The same change reaches owners. A homeowner can now build a Class 10a building on their own, without owner-builder approval, as long as the work is worth less than $50,000. Whoever builds it, the work must comply with the applicable building standards in the National Construction Code.
| Class 10a work | Who may build it |
|---|---|
| Valued at less than $50,000 | A registered building contractor is not required. Smaller service providers and handyman businesses may build it, and so may the homeowner, without owner-builder approval. |
| Valued at $50,000 or more, needing a building permit, inside the Building Services Board’s area | Contractor registration is the registration that lets a business provide services as a builder for this work. |
| Any value | A registered building contractor may build it, and the building permit requirements still apply. |
Any building work valued under $20,000 needs no registered builder in any case, and neither does work that needs no building permit. The guide to builder registration sets out the full path, exemptions included.
What stays in place without a registered builder
Building and Energy’s questions and answers on the new Class 10a threshold name protections that remain, among them:
- The owner must make sure that a building permit, where one is required, is obtained from the local government before construction starts.
- Penalties apply “if a building permit is not granted”.
- A complaint about building work that is unsatisfactory or defective can be made to the Building Commissioner.
- The contract must be written down and signed by both parties.
- A progress payment may cover only work that has actually been done.
Applying, and what it costs
Building permits are granted by the local government permit authority for the area where the work will be done, and that authority is the one to ask whether your patio or shed needs one. The forms used in the approvals process are approved by the Building Commissioner, and the local government assesses the application, so Building and Energy recommends contacting it about what it will need and the local laws to know.
Two charges come with a permit: the application fee and the Building Services Levy, which is payable on building permits and certificates. Both turn on the value of the work, and Schedule 1 of the Building Regulations 2012 sets how that value is worked out, as the sum of its listed components including GST.
| Charge | How it is set (Building and Energy, page last updated 4 August 2026) |
|---|---|
| Certified application for a building permit | For a Class 1 or Class 10 building or incidental structure: 0.19% of the estimated value of the work, as the permit authority determines it, and not less than $121.00 |
| Uncertified application for a building permit | 0.32% of the estimated value of the work, as the permit authority determines it, and not less than $121.00 |
| Building Services Levy on a building permit | 0.137% of the value of the work where it is over $45,000; $61.65 where it is $45,000 or less |
Building and Energy lists the two kinds of application side by side, certified and uncertified, each with its own fee; ask your local government which applies to your plans. Work done without approval is valued differently: the value of unauthorised work is its current value as the permit authority determines it.
As incidental structures, meaning structures attached or incidental to a building, retaining walls, fences and swimming pools are on the list of work exempt from registration as a building contractor, and so is installing timber decking. That is a different question from the permit. The registration rules apply in an area the state prescribes, which takes in 122 of Western Australia’s local governments; in some areas of low population only the major town sites are included. A pool always needs building approval, and the guide to pool barriers covers what follows.